Exercise machine



FIG. 1 is a front elevational view of the exercise machine showing our new design;

FIG. 2 is a side elevational view as viewed from the left of FIG. 1;

FIG. 3 is a side elevational view as viewed from the right of FIG. 1;

FIG. 4 is a rear elevation thereof; and,

FIG. 5 is a top plan view thereof.

The bottom of the exercise machine is plain and unornamented. 

The ornamental design for an exercise machine, as shown and described. 